Electronic Speedo - Convert?

[Wishin]

Right, so I'm getting the bits 'n pieces together to convert my Ceffy to use an RB25DET gearbox and one of the differences is the speedo drive (electronic in an R33 Skyline vs mechanical in the Cefiro).

So...instead of buying the Navara speedo drive, mangling it and then having to either live with my speedo being out or going to get it adjusted....is there a relatively cost-effective way to swap to using an electronic speedo? Did a bit of Googling but nothing obvious came up....

Cheers,

Matt

[daisu]

Here are some of my ideas.

Get your hands on an R33 cluster, disassemble it and try to fit the speedo section into your cefiro cluster. Can't guarantee this will be accurate as you will probably stuff the calibration when you remove and replace the needle.

Alternatively, get a cluster from a 180sx (or maybe S13) the models with a HUD had a digital readout on the cluster, you could put that into your cluster.

Either that or try and make the clusters fit in your dash, though you'll have to rewire the plugs on the back of the cluster.

You'll probably find the speedo will still be inaccurate depending on things like converting to manual from auto, different diff ratio, wheel/tyre size.

At least with an electronic speedo you can buy frequency adjusters from places like jaycar, Then you can compare it to something like a GPS and tweak the calibration yourself.

[funkymonkey]

you could get an HKS Camp, Apexi Multichecker or any other digital readout device and plug it straight into your ECU. No gurantees on if it'll be accurate though. I use an Apexi Multichecker on my 32 as my speedo's out by a little bit.

[daisu]

Probably the easiest option, plug the R33 electronic speed sensor in the gearbox, wire it up to the ECU and wire the multichecker/RSM/whatever meter onto that.

[Vinesh]

some what funny.. i had the same problem every one says change the speedo sensor. get your hands on a b14 sentra instrument panel. this speedometer is eletric and fits exactly into place of ypur old cable type one. run four wires coming out the back of it and hook it up only problem is it only goes to 180. but other than that u could change the wallpaper to match back your original instrument panel i did this conversion on a c33 instrument panel works fine.

[brada31ke70]

why not use the navara speedo sender and mount the r33 speedo wheel on it, still use the cable?

[Vinesh]

why not use the navara speedo sender and mount the r33 speedo wheel on it, still use the cable?

to me modifying that gear to fit wouldnt exactly be balance i rather just leave vital moving parts as is and looked for a alternative. mine works very well up to now and in my country i couldnt source the navara speedo so i just say lemme tell u guys what i did

[Lum]

you could get an HKS Camp, Apexi Multichecker or any other digital readout device and plug it straight into your ECU. No gurantees on if it'll be accurate though. I use an Apexi Multichecker on my 32 as my speedo's out by a little bit.

But where does that electric signal to the ECU come from? I thought the speedo in the dash did the conversion from mechanical to electrical and sent it to the ECU?

I guess you could wire up the multichecker directly to the output on the R33 gearbox, though I seem to remember somewhere that the speedo still does some kind of conversion, meaning the speedo converts the electrical into a different format before sending it on to the ECU, in which case this plan wouldn't work. Best check an R33 wiring diagram to see if I'm talking out of my arse or not.

Also a Defi VSD would probably be a better option than a multichecker. That is what I'm using with my stock Ceffy to get an MPH readout since I'm in the UK. It works very well as my sole speedo.

Edited November 5, 2009 by Lum

[daisu]

Lum is correct, the speedometer converts the cable speed to an electrical signal and sends it to the ECU.

I would suspect that in the vehicles with speed sensors on the gearbox, that it goes directly to the ECU.

Items like the speed checker and defi VSD plug into the consult connector, which uses a serial connection to communicate and retrieve data from the ECU, so it is highly unlikely that you would beable to connect the speed sensor directly to any of these.

[Dorigecko]

If I may...

to use a cable from the speedo to the gearbox, what exactly is required in terms of parts and mounting?

i can get speedo cables made up to have whatever ends they need.

[daisu]

According to commodore forums, all you need is the speed sensor gear from a VL turbo. It is the correct size to fit in an RB25 box and it fits the speedo cable (VL, R32, C33, A31 all use the same cable).

[Nic_A31]

If i may also....what do the 25SE use?

Theyve got RB25DE, so would they have a 25 gearbox?

and if so...would they use eletrical or cable?

Either way, go to NZ and find a smashed up 25SE (yeah its sad but thats what they do over there).

[brada31ke70]

all you need is a navara speedo sender, the r33 speedo sender gear, mount the two together, make another cut in the navara speedo sender, works a treat. if thats too hard, use the navara whole unit but your speedo will be out by about 30ks at 1oo. the cefiro speedo cable will screw straight into the navara speedo sender, no need to modify the speedo cable

[daisu]

If i may also....what do the 25SE use?

Theyve got RB25DE, so would they have a 25 gearbox?

and if so...would they use eletrical or cable?

Either way, go to NZ and find a smashed up 25SE (yeah its sad but thats what they do over there).

Pretty sure the 25SE and the gts-25 use the smaller gearboxes (same as rb20).